Explosions are pretty cool as long as they are used carefully. I've been trying to create a realistic explosion for a while.

Test 1:
This one is supposed to be a small ground explosion. Still working on debris and other details.

Test 2:
Making a nuclear explosion is pretty hard. I worked for a long time to get the particles to move in a satisfactory manner. It still isn't perfect. Near the end the base particles start to decay, and the ring evolves into the donut shaped array of attraction particle modifiers.